Motor vehicle window assemblies may include one or more sliding windows that move either in a horizontal or vertical direction. Various sliding window assemblies may be operated manually or may be driven by an actuator or motor.
For example, sliding window assemblies may be used as rear slider windows or back lights for pick up truck type vehicles. In such applications, the window assemblies may be housed within a frame that is positioned in an opening in a back portion of the cab of the pick up. The sliding windows may move horizontally relative to the frame to allow for opening and closing of a portion of the window assembly. Typically, such sliding window assemblies may include one or more fixed windows and a moveable window.
Sliding window assemblies may be power operated and may utilize various guide mechanisms or systems to open and close the sliding window. For example, a pull-drive system including cables that apply a pulling force to the sliding window in opposing directions to open and close the sliding window may be utilized. For example U.S. Pat. Nos. 5,724,769, 5,822,922, 6,026,611, 7,437,852 and 6,766,617 provide examples of power sliding window assemblies the disclosures of which are herein incorporated by reference in their entirety.
It is also desirable to provide the rear back light or window assembly of a pick-up truck with a defrost grid to remove fog from the windows and apply a heating force to melt ice or snow that may accumulate on the back light or window. In such a heated back light wires may be imbedded in the glass which carries an electrical current to heat the glass locally and melt or remove fog or ice and snow from the window. In such applications, the sliding window may include contacts that are linked with a fixed window to transmit electrical current from a power source to the various windows of the window assembly. However, it is desirable to have the defrost current disabled when the sliding window is being moved to an open position to prevent an arc being formed between the gap between contacts of the sliding window and the fixed window. There is therefore a need in the art for a heated sliding window assembly including a defrost grid on one or more fixed windows and a movable window such that current is cut off when the sliding window opens.